Indicator



July 13 1926.

F. J. METZGER INDI CAT 0R Filed April 4. 1922 l- Patented v'July 13, 1926.- r.

i determining the nected to" the ignition UNIT-en STAT-s PAT FLOYD J. unrrzenn, for Nnw rolex, N. Y., i iNcoaroanrnn, a coaroanzrroN or L .1,592,533 ENT OFFICE.

AssIGNon 'ro AIR REDUCTION COMPANY,

NEW' YORK.

lizin'ncnrorc..

Thisinvention relates to an indicator for systems of internal combustion engines, and particularly to a device whichmay bacon# system of a multr cylinder engine to indicate the ignition conby the discharge of high tension electric cur# rents through the gas. lof neon is of a vivid which readily `serves of thepassagepof current.- The gas is sufli The Hash in the case to inform an observer'J i 4.iefltl' Sensitive. S0 that# --S not necessary vin capacity media which materially increase the?" 7 sented in brightness takes place. l. l

' 'It vhas been `suggested heretofore. to em tionsenglnes,

condition ing terminals and f to {provideelectrodes extending into th'ein-v ..20 l ,electrodes may be' used, the ends of the tubes -dicator receptacles .citubes, and Ialthough thepreferred'embodiment of the invention are provided withl externally disposed of the Hash when -the 1discharge` ploy tubescontainmg neon' as indicators for the ignition conditions: f internal combusand `a device which is adapted tobe" manually applied to the spark plugs 'or the conductors leading thereto is` de- No. 475,778. Such a device isuseful when the operator can obtain access to the engine,

tions are diierent,however,w en the en ne is loaded and the operator of a motor-driven lvehicle fr uently desires to determine the o the ignition. stem while he is operating the vehicle ando serving some peculiar condition of operation which has come to'bis attention.

` The 'object of the v resent invention is the provision of a slmp e and inexpensive device which may -be conveniently arranged4 and connected to the ignitionfsystem to indicate, without fthe necessity of manipulation, the condition of the respective sparkgenerally of the ignition system.

'Further ob'ects and advantages of the in vention will apparent as it is better understood by reference tothe following speccondition of the ignitionv reddish-orange color desiredonformation taining a suitable gas,

pressure may vary Widely.

my copending application Serial appnoauon'med apra '4, 1922.: serial No. 549.508.

iication and accompanying drawing, in i which 1 is a front elevation of the device.;

Figa 2 is a plan .view of the deviceillustrating'the arrangement ofthe conductors which convey current to the tubes. A

Fig. 3 is a transverse section on the line 3`.3 of Fig. 1.

Referring ,to the drawing, llindicates a i -suitable casing whihimay be constructed of any desired material, although preferably the materia-lshould be of an insulating char-I acter sucht as vulcanite or a hard phenol condensation product. The casing is prefer`l ablya solid block of rectangular cross' section, although it may, of course, have any It is provided, as indicated, with a plurality' of recesses 6 each adapted to receive an indicator tube 7 confor example, neon. The neon is preferably under a reduced pressure of approximately 10 mm., though the To insure the production of a brilliant Hash, the ends of the tube may be 'partially surrounded by capacity media which may consist of metal lfoil or metal wool 8, the latter being preferred because of the ease With which it may be assembled with the tube and casing..

When the tubes are thus disposed in the rgcesses, they may be observed through openings 9 provided in the front of the casing.

'A cover 1()4 is bosses l1 conforming i-n shape and size to the ends of the recesses 6 and, adapted to enter the same for the purpose of sealing the recesses when the kcover is` secured in place by screws 12. Contacts 13 'extend through the bosses into engagement with the capacity media at the `adjacent @gids of the tubes, and these contacts are lconnected by conductors 14 to the sparking terminals, i. e., the central electrodes of the spark plugs in preferably provided with the engine .(not shown) or to conductors of pro- It is to be' the provision of a closed"- 5 for each cylinder of the through the tubes.

From the foregoing it will be observed "hat when the device herein described is 'secured, for example, to the instrument board of the vehicle and the several contacts areV the vehicle in Which the device is installed connected by suitaole conductors to the respective sparking terminals, the driver of may determine at any moment the condition of the sparking` terminals in any ofthe several cylinders. In the normal operation of the engine, the`several tubes y will. flash intermittently as each discharge occurs at the corresponding spark gap in the engine. If a bright iash occurs, the plug is in proper condition for continued operation 'A very intense iiash indicates that the spark gap of the particular plug is too wide. YA dim flash indicates that the plug is partially foul enables the driver of the vehicle to-maintaln the `ignition system in rst class operative condition ause he may continuously lobserve" the operation of the systmiidis mmediately advised of any deterioration of the spark plugs. If defects appear he may readily overcome them before any injury to the mechanism has occurred.

It isdto be understoodthat `the invention may be varied inits details Withoutdepartingkfrom the essential features thereof as hereinafter claimed.

Ifclaim: n v An indicator comprising a casing of insulating material having a plurality of sep-- arate Vcompartments therein' and openingsl in its walls opposite each compartment, a cover for the casing having bosses thereon which extend into .the compartments, a tube in each compartment which is adaptedto become luminous under the influence of a high tension electrical current, capacity mediadislposedin each compartment' at the ends ofthe and a plurality of conductors extending through the cover of the casing and conor broken, and irregularity of theflash showvstacting ywiththe capacity media in each comf that the plug is firing intermittently. .If no partment.

flash occurs, the plug is foul or there is'no current iowing thereto. v The installation of lthe device described.l

' In testimoify whereof I aix my signature.

FLOYD J. im'rzGER. 

